<template>
    <section class="real-app">
        <input 
            type="text"
            class="add-input"
            autofocus="autofocus"
            placeholder="接下去要做啥"
            @keyup.enter="addTodo"
        >
        <Item 
            :todo="todo"
            v-for="todo in filterdTodos"
            :key="todo.id"
            @del="deleteTodo"
        />
        <Tabs 
            :filter="filter"
            :todos="todos"
            @toggle="toggleFilter"
            @clearAll="clearAllCompleted"
        />
    </section>
</template>

<script>
import Item from './item.vue'
import Tabs from './tabs.vue'
let id = 0;
export default {
    data(){
        return {
            todos:[],
            filter:'all'
        }
        
    },
    components:{
        Item,
        Tabs
    },
    computed:{
         filterdTodos(){
             if(this.filter === 'all'){
                 return this.todos
             }
             const completed = this.filter === 'completed';
             return this.todos.filter(todo => completed === todo.completed)
         }
    },
    methods:{
        addTodo(e){
            this.todos.unshift({
                id: id++,
                content: e.target.value.trim(),
                completed: false,
            })
            e.target.value = ''
        },
        deleteTodo(id) {
            this.todos.splice(this.todos.findIndex(todo => todo.id === id), 1)
        },
        toggleFilter(state){
            this.filter = state
        },
        clearAllCompleted(){
            this.todos = this.todos.filter(todo => !todo.completed)
        }
    }

}
</script>

<style lang="stylus" scoped>
.real-app
    width 600px
    margin 0 auto
    box-shadow 0 0 5px #666

.add-input
    position relative
    margin 0
    width 100%
    font-size 24px
    font-family inherit
    font-weight inherit 
    line-height 1.4em
    border none
    outline none 
    color inherit 
    box-sizing border-box
    font-smoothing antialiased
    padding 16px 16px 16px 36px
    border none
    box-shadow inset 0 -2px 1px rgba(0, 0, 0, 0.03)
</style>
